Mol-ecular structure, DFT studies and Hirshfeld analysis of anthracenyl chalcone derivatives

The mol-ecular and crystal structure of two new chalcone derivatives, (E)-1-(anthracen-9-yl)-3-[4-(piperidin-1-yl)phen-yl]prop-2-en-1-one, C₂₈H₂₅NO, (I), and (E)-1-(anthracen-9-yl)-3-[4-(di-phenyl-amino)-phen-yl]prop-2-en-1-one, C₃₅H₂₅NO, (II), with the fused-ring system at the same position are described. In the crystals of (I) and (II), the mol-ecules are linked via C-H⋯O hydrogen bonds into inversion dimers, forming R₂²(22) and R₂²(14) ring motifs, respectively. Weak inter-molecular C-H⋯π inter-actions further help to stabilize the crystal structure, forming a two-dimensional architecture. The mol-ecular structures are optimized using density functional theory (DFT) at B3LYP/6-311 G++(d,p) level and compared with the experimental results. The smallest HOMO-LUMO energy gaps of (I) (exp . 2.76 eV and DFT 3.40 eV) and (II) (exp . 2.70 eV and DFT 3.28 eV) indicates the suitability of these crystals in optoelectronic applications. All inter-molecular contacts and weaker contributions involved in the supra-molecular stabilization are investigated using Hirshfeld surface analysis. The mol-ecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the mol-ecules.